Question

In a class experiment to determine information about free-fall acceleration, a watermelon and a pumpkin are each set to fall from the back of the stands at your football stadium.

a. If the watermelon and the pumpkin are both dropped at the same time, which one will hit the ground first?

b. If the watermelon is thrown downward with an initial speed of 10 m/s and the pumpkin is dropped, which one will hit the ground first? Show calculation to support your answer.

c. If it takes the watermelon 1 second to reach the ground when it is thrown downward at 10 m/s, how tall are the stands?

d. How long does it take the pumpkin to reach the ground if it is dropped from this height you calculated in part c?

Answer 1

Answer:

a) They both hit the ground at the same time

b) Watermelon will hit first, since its speed is faster than the pumpkin speed

c) h = 29,6 m

d)t = 3,02 sec

Explanation:

Equations for fall free movement are:

vf = v₀ + g*t       when   v₀ = 0   (dropped case)  vf = g*t

h = v₀*t + 1/2*g*t²

a) For both ( watermelon and pumpkin) the equation of speed is the same:

vf = g*t²    Both will have the same speed second through second

They both hit the ground at the same time

b) Now is watermelon is thrown with v₀ = 10 m/s

Watermelon will hit first since its speed is faster than the pumpkin speed

vf(watermelon) =  10 + g*t

vf₂ (pumpkin)   =  g*t

c) h = v₀*t + (1/2)*g*t²

h = (10)*1 + (1/2)*9,8*1

h = 10 + 19,6

h = 29,6 m

d)  h = g*t

t = 29,6/9,8

t = 3,02 sec